■ 가우시안 커널(Gaussian Kernel)을 계산하는 방법을 보여준다.
▶ BitmapHelper.cs
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 |
using System; using System.Drawing; using System.Drawing.Imaging; using System.Runtime.InteropServices; namespace TestProject { /// <summary> /// 비트맵 헬퍼 /// </summary> public static class BitmapHelper { //////////////////////////////////////////////////////////////////////////////////////////////////// Method ////////////////////////////////////////////////////////////////////////////////////////// Static //////////////////////////////////////////////////////////////////////////////// Public #region 비트맵 로드하기 - LoadBitmap(filePath) /// <summary> /// 비트맵 로드하기 /// </summary> /// <param name="filePath">파일 경로</param> /// <returns>비트맵</returns> public static Bitmap LoadBitmap(string filePath) { using(Bitmap bitmap = new Bitmap(filePath)) { return new Bitmap(bitmap); } } #endregion #region 가우시안 커널 계산하기 - CalculateGaussianKernel(length, weight) /// <summary> /// 가우시안 커널 계산하기 /// </summary> /// <param name="length">길이</param> /// <param name="weight">가중치</param> /// <returns>가우시안 커널 배열</returns> public static double[,] CalculateGaussianKernel(int length, double weight) { double[,] filterArray = new double [length, length]; double totalSummary = 0; int kernelRadius = length / 2; double distance = 0; double eulerCalculated = 1.0 / (2.0 * Math.PI * Math.Pow(weight, 2)); for(int filterY = -kernelRadius; filterY <= kernelRadius; filterY++) { for(int filterX = -kernelRadius; filterX <= kernelRadius; filterX++) { distance = ((filterX * filterX) + (filterY * filterY)) / (2 * (weight * weight)); filterArray[filterY + kernelRadius, filterX + kernelRadius] = eulerCalculated * Math.Exp(-distance); totalSummary += filterArray[filterY + kernelRadius, filterX + kernelRadius]; } } for(int y = 0; y < length; y++) { for(int x = 0; x < length; x++) { filterArray[y, x] = filterArray[y, x] * (1.0 / totalSummary); } } return filterArray; } #endregion #region 회선 필터 적용하기 - ApplyConvolutionFilter(sourceBitmap, filterArray, factor, bias) /// <summary> /// 회선 필터 적용하기 /// </summary> /// <param name="sourceBitmap">소스 비트맵</param> /// <param name="filterArray">필터 배열</param> /// <param name="factor">인자</param> /// <param name="bias">바이어스</param> /// <returns>비트맵</returns> public static Bitmap ApplyConvolutionFilter(Bitmap sourceBitmap, double[,] filterArray, double factor = 1, int bias = 0) { BitmapData sourceBitmapData = sourceBitmap.LockBits ( new Rectangle(0, 0, sourceBitmap.Width, sourceBitmap.Height), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb ); byte[] sourceByteArray = new byte[sourceBitmapData.Stride * sourceBitmapData.Height]; byte[] targetByteArray = new byte[sourceBitmapData.Stride * sourceBitmapData.Height]; Marshal.Copy(sourceBitmapData.Scan0, sourceByteArray, 0, sourceByteArray.Length); sourceBitmap.UnlockBits(sourceBitmapData); double blue = 0.0; double green = 0.0; double red = 0.0; int filterWidth = filterArray.GetLength(1); int filterHeight = filterArray.GetLength(0); int filterOffset = (filterWidth - 1) / 2; int sourceOffset = 0; int targetOffset = 0; for(int offsetY = filterOffset; offsetY < sourceBitmap.Height - filterOffset; offsetY++) { for(int offsetX = filterOffset; offsetX < sourceBitmap.Width - filterOffset; offsetX++) { blue = 0; green = 0; red = 0; targetOffset = offsetY * sourceBitmapData.Stride + offsetX * 4; for(int filterY = -filterOffset; filterY <= filterOffset; filterY++) { for(int filterX = -filterOffset; filterX <= filterOffset; filterX++) { sourceOffset = targetOffset + (filterX * 4) + (filterY * sourceBitmapData.Stride); blue += (double)(sourceByteArray[sourceOffset]) * filterArray[filterY + filterOffset, filterX + filterOffset]; green += (double)(sourceByteArray[sourceOffset + 1]) * filterArray[filterY + filterOffset, filterX + filterOffset]; red += (double)(sourceByteArray[sourceOffset + 2]) * filterArray[filterY + filterOffset, filterX + filterOffset]; } } blue = factor * blue + bias; green = factor * green + bias; red = factor * red + bias; blue = (blue > 255 ? 255 : (blue < 0 ? 0 : blue )); green = (green > 255 ? 255 : (green < 0 ? 0 : green)); red = (red > 255 ? 255 : (red < 0 ? 0 : red )); targetByteArray[targetOffset ] = (byte)(blue); targetByteArray[targetOffset + 1] = (byte)(green); targetByteArray[targetOffset + 2] = (byte)(red); targetByteArray[targetOffset + 3] = 255; } } Bitmap targetBitmap = new Bitmap(sourceBitmap.Width, sourceBitmap.Height); BitmapData targetBitmapData = targetBitmap.LockBits ( new Rectangle(0, 0, targetBitmap.Width, targetBitmap.Height), ImageLockMode.WriteOnly, PixelFormat.Format32bppArgb ); Marshal.Copy(targetByteArray, 0, targetBitmapData.Scan0, targetByteArray.Length); targetBitmap.UnlockBits(targetBitmapData); return targetBitmap; } #endregion } } |
▶ MainForm.cs
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 |
using System.Drawing; using System.Windows.Forms; namespace TestProject { /// <summary> /// 메인 폼 /// </summary> public partial class MainForm : Form { //////////////////////////////////////////////////////////////////////////////////////////////////// Constructor ////////////////////////////////////////////////////////////////////////////////////////// Public #region 생성자 - MainForm() /// <summary> /// 생성자 /// </summary> public MainForm() { InitializeComponent(); double[,] kernelArray = BitmapHelper.CalculateGaussianKernel(5, 5.5); Bitmap sourceBitmap = BitmapHelper.LoadBitmap("IMAGE\\sample.jpg"); Bitmap targetBitmap = BitmapHelper.ApplyConvolutionFilter(sourceBitmap, kernelArray, 1, 0); this.pictureBox.SizeMode = PictureBoxSizeMode.Zoom; this.pictureBox.Image = targetBitmap; } #endregion } } |
